Open AccessQuorum quenching activity in Anabaena sp. PCC 7120: identification of AiiC, a novel AHL‐acylase
Author(s) -
Romero Manuel,
Diggle Stephen P.,
Heeb Stephan,
Cámara Miguel,
Otero Ana
Publication year - 2008
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2007.01046.x
Subject(s) - quorum quenching , quorum sensing , bacteria , biochemistry , cyanobacteria , microbiology and biotechnology , biology , anabaena , biofilm , genetics
Many bacteria use quorum sensing (QS) to coordinate responses to environmental changes. In Gram‐negative bacteria, the most extensively studied QS systems rely on the use of N ‐acylhomoserine lactones (AHLs) signal molecules. Some bacteria produce enzymes that are able to inactivate AHL signals produced by other bacteria and hence interfere with QS‐mediated processes via a phenomenon known as quorum quenching. Acylase‐type AHL degradation activity has been found in the biomass of the filamentous nitrogen‐fixing cyanobacterium Anabaena ( Nostoc ) sp. PCC 7120, being absent from the culture media. The gene all3924 has been identified and cloned whose product exhibits homology to the acylase QuiP of Pseudomonas aeruginosa PAO1, demonstrating that it is at least partially responsible for the AHL‐acylase activity. The recombinant enzyme, which was named auto‐inducer inhibitor from Cyanobacteria (AiiC), shows broad acyl‐chain length specificity. Because the presence of AHLs in the biomass of nitrogen‐fixing cultures of Anabaena sp. PCC 7120 has been described recently, AiiC could represent a self‐modulatory system to control the response to its own QS signals but could also be involved in the interference of signalling within complex microbial communities in which Cyanobacteria are present.